/*********************************************************
 *
 * MDCM
 *
 * Modifications github.com/issakomi
 *
 *********************************************************/

/*=========================================================================

  Program: GDCM (Grassroots DICOM). A DICOM library

  Copyright (c) 2006-2011 Mathieu Malaterre
  All rights reserved.
  See Copyright.txt or http://gdcm.sourceforge.net/Copyright.html for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

#include "mdcmSubject.h"
#include "mdcmSmartPointer.h"
#include "mdcmCommand.h"
#include "mdcmEvent.h"
#include <list>

namespace mdcm
{
class Observer
{
public:
  Observer(Command * c, const Event * event, unsigned long tag)
  :
  m_Command(c),
  m_Event(event),
  m_Tag(tag) {}
  virtual ~Observer() { if (m_Event) delete m_Event; }
  SmartPointer<Command> m_Command;
  const Event * m_Event;
  unsigned long m_Tag;
};

class SubjectInternals
{
public:
  SubjectInternals() {m_Count = 0;}
  ~SubjectInternals();
  unsigned long AddObserver(const Event & event, Command * cmd);
  unsigned long AddObserver(const Event & event, Command * cmd) const;
  void RemoveObserver(unsigned long tag);
  void RemoveAllObservers();
  void InvokeEvent(const Event & event, Subject * self);
  void InvokeEvent(const Event & event, const Subject * self);
  Command * GetCommand(unsigned long tag);
  bool HasObserver(const Event & event) const;
  bool PrintObservers(std::ostream& os, std::string indent) const;

private:
  std::list<Observer* > m_Observers;
  unsigned long m_Count;
};

SubjectInternals::~SubjectInternals()
{
  for(std::list<Observer* >::iterator i = m_Observers.begin();
      i != m_Observers.end();
      ++i)
  {
    delete (*i);
  }
}

unsigned long SubjectInternals::AddObserver(const Event & event, Command * cmd)
{
  Observer * ptr = new Observer(cmd, event.MakeObject(), m_Count);
  m_Observers.push_back(ptr);
  m_Count++;
  return ptr->m_Tag;
}

unsigned long SubjectInternals::AddObserver(const Event & event, Command * cmd) const
{
  Observer * ptr = new Observer(cmd, event.MakeObject(), m_Count);
  SubjectInternals * me = const_cast<SubjectInternals *>(this);
  me->m_Observers.push_back(ptr);
  me->m_Count++;
  return ptr->m_Tag;
}

void SubjectInternals::RemoveObserver(unsigned long tag)
{
  for(std::list<Observer* >::iterator i = m_Observers.begin();
      i != m_Observers.end();
      ++i)
  {
    if((*i) && (*i)->m_Tag == tag)
    {
      delete (*i);
      m_Observers.erase(i);
      return;
    }
  }
}

void SubjectInternals::RemoveAllObservers()
{
  for(std::list<Observer* >::iterator i = m_Observers.begin();
      i != m_Observers.end();
      ++i)
  {
    if(*i) delete (*i);
  }
  m_Observers.clear();
}

void SubjectInternals::InvokeEvent(const Event & event, Subject * self)
{
  for(std::list<Observer* >::iterator i = m_Observers.begin();
      i != m_Observers.end(); ++i)
  {
    const Event * e =  (*i)->m_Event;
    if(e && e->CheckEvent(&event))
    {
      (*i)->m_Command->Execute(self, event);
    }
  }
}

void SubjectInternals::InvokeEvent(const Event & event, const Subject * self)
{
  for(std::list<Observer* >::iterator i = m_Observers.begin();
      i != m_Observers.end(); ++i)
  {
    const Event * e =  (*i)->m_Event;
    if(e && e->CheckEvent(&event))
    {
      (*i)->m_Command->Execute(self, event);
    }
  }
}

Command * SubjectInternals::GetCommand(unsigned long tag)
{
  for(std::list<Observer* >::iterator i = m_Observers.begin();
      i != m_Observers.end(); ++i)
  {
    if ((*i) && (*i)->m_Tag == tag)
    {
      return (*i)->m_Command;
    }
  }
  return 0;
}

bool SubjectInternals::HasObserver(const Event & event) const
{
  for(std::list<Observer* >::const_iterator i = m_Observers.begin();
      i != m_Observers.end(); ++i)
  {
    const Event * e =  (*i)->m_Event;
    if(e && e->CheckEvent(&event))
    {
      return true;
    }
  }
  return false;
}

bool SubjectInternals::PrintObservers(std::ostream & os, std::string indent) const
{
  if(m_Observers.empty())
  {
    return false;
  }

  for(std::list<Observer* >::const_iterator i = m_Observers.begin();
      i != m_Observers.end(); ++i)
  {
    const Event * e =  (*i)->m_Event;
    const Command * c = (*i)->m_Command; (void)c;
    if (e) {os << indent << e->GetEventName() << ")\n"; }
  }
  return true;
}

Subject::Subject() : Internals(new SubjectInternals)
{
}

Subject::~Subject()
{
  delete Internals;
}

unsigned long Subject::AddObserver(const Event & event, Command *cmd)
{
  return this->Internals->AddObserver(event,cmd);
}
unsigned long Subject::AddObserver(const Event & event, Command *cmd) const
{
  return this->Internals->AddObserver(event,cmd);
}

Command * Subject::GetCommand(unsigned long tag)
{
  return this->Internals->GetCommand(tag);
}

void Subject::InvokeEvent(const Event & event)
{
  this->Internals->InvokeEvent(event,this);
}

void Subject::InvokeEvent(const Event & event) const
{
  this->Internals->InvokeEvent(event,this);
}

void Subject::RemoveObserver(unsigned long tag)
{
  this->Internals->RemoveObserver(tag);
}

void Subject::RemoveAllObservers()
{
  this->Internals->RemoveAllObservers();
}

bool Subject::HasObserver(const Event & event) const
{
  return this->Internals->HasObserver(event);
}

}
